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Re: New 36W tremolo TMB project
Posted: Fri 04/02/21 11:39 am
by Bieworm
JMPGuitars wrote: ↑Fri 04/02/21 10:53 am
Bieworm wrote: ↑Fri 04/02/21 10:44 am
Josh.. I'm missing a 2uf cap for the cathode of V2B. I do have a 2.2uf 63V electrolytic cap. Should do the job, no?
I use a 3.3µF there, I think you'll be fine.
Why 3.3uf? Halfway cold clipper kinda thingy?
Question about the non using the fx loop..for now..it looks like there are parallel solder terminals to the 68k terminals. I guess I have to put a jumper wire in there.. correct?
Re: New 36W tremolo TMB project
Posted: Fri 04/02/21 1:59 pm
by JMPGuitars
Bieworm wrote: ↑Fri 04/02/21 11:39 am
Why 3.3uf? Halfway cold clipper kinda thingy?
Question about the non using the fx loop..for now..it looks like there are parallel solder terminals to the 68k terminals. I guess I have to put a jumper wire in there.. correct?
For more bottom end.
Yes, jumper if not using the 68K, or connect the wire further back if not using turrets. Solder the jumper on the top of the board in case you change your mind.
Re: New 36W tremolo TMB project
Posted: Sat 04/03/21 2:52 pm
by Bieworm
Here is some progress.. did some more power amp wiring. And I put a ground buss at the pots. It makes it easier on wiring the shields of shielded wires. I always find it hard to add the shielded wires at the pots... mostly because I already soldered the grounds and have to add the shields afterwards..
20210403_214708.jpg
Re: New 36W tremolo TMB project
Posted: Sat 04/03/21 2:58 pm
by JMPGuitars
Bieworm wrote: ↑Sat 04/03/21 2:52 pm
Here is some progress.. did some more power amp wiring. And I put a ground buss at the pots. It makes it easier on wiring the shields of shielded wires. I always find it hard to add the shielded wires at the pots... mostly because I already soldered the grounds and have to add the shields afterwards..
It might be fine, but technically the shields should not be sharing the preamp grounds. Shields are supposed to have their own connection to ground.
Personally, I shield the other end on the terminal strip using the ground lug.
If you find the preamp to be noisy, reverse the gain wire shielding end.
Re: New 36W tremolo TMB project
Posted: Sat 04/03/21 3:15 pm
by Bieworm
Thx for the tip!
In that case I need do put the shield of the input wire at the tube socket... but will leave it as is for now. If there's noise I will redo it ..
Re: New 36W tremolo TMB project
Posted: Sat 04/03/21 4:10 pm
by JMPGuitars
I just noticed... one of your outer foils is facing the wrong way.
Re: New 36W tremolo TMB project
Posted: Sat 04/03/21 5:21 pm
by Bieworm
JMPGuitars wrote: ↑Sat 04/03/21 4:10 pm
I just noticed... one of your outer foils is facing the wrong way.
Ah crap yeah!!! And a pretty significant one too.. sigh
Re: New 36W tremolo TMB project
Posted: Sat 04/03/21 7:35 pm
by TriodeLuvr
Bieworm wrote: ↑Sat 04/03/21 5:21 pm
JMPGuitars wrote: ↑Sat 04/03/21 4:10 pm
I just noticed... one of your outer foils is facing the wrong way.
Ah crap yeah!!! And a pretty significant one too.. sigh
Might not make a difference, depends where it's located in the circuit. The purpose of caps generally is to conduct AC signal from one end to the other with as little impediment as possible. On that basis, if the cap acts like an AC short, it doesn't matter which end is the foil.
Jack
Re: New 36W tremolo TMB project
Posted: Sun 04/04/21 2:17 am
by Bieworm
TriodeLuvr wrote: ↑Sat 04/03/21 7:35 pm
Bieworm wrote: ↑Sat 04/03/21 5:21 pm
JMPGuitars wrote: ↑Sat 04/03/21 4:10 pm
I just noticed... one of your outer foils is facing the wrong way.
Ah crap yeah!!! And a pretty significant one too.. sigh
Might not make a difference, depends where it's located in the circuit. The purpose of caps generally is to conduct AC signal from one end to the other with as little impediment as possible. On that basis, if the cap acts like an AC short, it doesn't matter which end is the foil.
Jack
Thanks Jack..
But I want the amp a right as possible. It's the cathode cap that has the negative end right there at the conjunction of itself and the end of the entire pot ground string..
Seems like the potentially largest noise introducer on the preamp ground.
Re: New 36W tremolo TMB project
Posted: Sun 04/04/21 3:55 am
by Bieworm
OTOH...couldn't I scope the difference in noise like it is built in now? It only is connected to ground side. If the difference in measurement is small enough I can let it be since it will be not so obvious in the end?
Re: New 36W tremolo TMB project
Posted: Sun 04/04/21 4:32 am
by TriodeLuvr
If it's a cathode bypass cap, and it's not electrolytic, it won't matter. In addition to everything else, the operating impedance at that point is low and not susceptible to noise pickup.
Re: New 36W tremolo TMB project
Posted: Sun 04/04/21 7:46 am
by JMPGuitars
I don't know how perceivable the difference would be over 1 cap's direction, but I've never seen anybody make an exception for cathode caps. I've also made plenty of quiet amps before I ever started marking the foils, so obviously the foil direction is not the most important point in building an amp...but it seems to help.
Re: New 36W tremolo TMB project
Posted: Sun 04/04/21 12:50 pm
by Bieworm
V1, 2 and 3 wired...
20210404_194835.jpg
Re: New 36W tremolo TMB project
Posted: Mon 04/05/21 8:56 am
by Bieworm
Damn... it's finished. Voltages are on the high side, but wall voltage is extremely high at the moment, so I will have to wait before I zener this one down.
All in all pretty in the same ballpark, so I decided to light it up. Biased at 83%, so is this safe? It says 24.8W/ tube ... on a 36W OT???. Man this sounds huuuuuge!!!!
https://www.dropbox.com/s/qg5bekvobi8ty ... e.m4a?dl=0
20210405_155205.jpg
20210405_155136.jpg
Re: New 36W tremolo TMB project
Posted: Mon 04/05/21 9:52 am
by Bieworm
Ok, so I added a IN 5359 zener, 5W 24V... now we're in business!
20210405_165107.jpg
Re: New 36W tremolo TMB project
Posted: Mon 04/05/21 1:32 pm
by Riffmonster
Bieworm wrote: ↑Mon 04/05/21 8:56 am
Damn... it's finished. Voltages are on the high side, but wall voltage is extremely high at the moment, so I will have to wait before I zener this one down.
All in all pretty in the same ballpark, so I decided to light it up. Biased at 83%, so is this safe? It says 24.8W/ tube ... on a 36W OT???. Man this sounds huuuuuge!!!!
https://www.dropbox.com/s/qg5bekvobi8ty ... e.m4a?dl=0
20210405_155205.jpg20210405_155136.jpg
Sounds great, I love the tremolo!!
Re: New 36W tremolo TMB project
Posted: Mon 04/05/21 1:35 pm
by Bieworm
Riffmonster wrote: ↑Mon 04/05/21 1:32 pm
Bieworm wrote: ↑Mon 04/05/21 8:56 am
Damn... it's finished. Voltages are on the high side, but wall voltage is extremely high at the moment, so I will have to wait before I zener this one down.
All in all pretty in the same ballpark, so I decided to light it up. Biased at 83%, so is this safe? It says 24.8W/ tube ... on a 36W OT???. Man this sounds huuuuuge!!!!
https://www.dropbox.com/s/qg5bekvobi8ty ... e.m4a?dl=0
20210405_155205.jpg20210405_155136.jpg
Sounds great, I love the tremolo!!
Thx.. and the amp is dead quiet too. The noise you hear is me sitting right in front of it with a tele
Re: New 36W tremolo TMB project
Posted: Mon 04/05/21 7:19 pm
by TriodeLuvr
Great smooth tone and beautiful playing. I need lessons...
Congrats on a successful build!
Jack
Re: New 36W tremolo TMB project
Posted: Mon 04/05/21 10:08 pm
by ViperDoc
Great sounds. And that PCB is hot and sexy.
Re: New 36W tremolo TMB project
Posted: Mon 04/05/21 10:47 pm
by Bieworm
Love that pcb!!! Leaves less room for error + it's great quality
Thanks guys! Thanks Josh !